The present invention relates to a method and device for controlling aggregates in a vehicle according to the definition of the species in the independent claims.
The number of aggregates built into vehicles is growing steadily. These aggregates emit noises which, in certain operating situations, are perceived as being disturbing and a nuisance by the passengers in the vehicle. In order to tone down these disturbing and irritating noises, the aggregates are controlled by complex methods for the purpose of reducing the noise.
To do this, in DE 195 48 248 A1 a method and a device for controlling the pump of an electrohydraulic braking system is proposed. In this instance, hydraulic fluid from a pressure accumulator is applied through valves into the wheel brake cylinder, the pressure accumulator being loaded using a pump. The pump is controlled in a performance-regulated manner in such a way that charging the pressure accumulator by the pump is accomplished with as little noise as possible. This is achieved by a pulse/pause ratio specifiable according to demand, especially in view of resonance effects and/or pressure in the pressure accumulator. For this, the pump is operated at a minimally required power depending upon the situation, in order to avoid the development of loud noise.
DE 44 29 373 A1 shows the control of a further aggregate in a vehicle, an electromagnetic valve, in particular a braking system, which is also carried out under the requirement of minimizing the noises that occur. This is achieved in that, during the usual changeover from a first to a second switching position, in particular in the flow-through direction, in a first phase, the current for operating the valve falls off for a predefined time, according to a certain function, from a first to a third current value, and in a second phase it remains approximately constant, the third current value lying above a second current value, which is used to achieve the second switching position. Here too, a complex method of limiting the development of noise is shown.
A control serving the same purpose, that is noise reduction, is shown in DE 199 08 992 A1. In this document, in a generator system as the aggregate for an internal combustion engine, noise development of the generator is reduced by lowering the excitation current under certain circumstances. Lowering the excitation current is done with the aid of a control element which ascertains the conditions for lowering the current from supplied or stored data, and gives out corresponding control signals. In this connection, a role is played by the generator temperature and the structure-borne noise recorded by means of a sensor. Here too, a very costly method is used to keep the generator""s noise emission low.
It has been shown that the cited related art is not able to obtain optimal results in every respect. Thus, in spite of costly control methods, a loss of portions of the possible operating range of aggregates contained in the vehicle is created because of the noise reduction measures. And so, a certain loss of performance, caused by the compromise between the minimum required control, from a technical functioning point of view, and the maximum desired control from a noise technology point of view cannot be avoided in the related art.
On the other hand, noises caused by the control of the aggregates are not perceived as disturbing in some situations, or rather they are not noticeable because of other noises. But this effect is not considered by the related art in the control of the aggregates. And yet, the temporal and spectral overriding effects causing this are sufficiently known in psychoacoustics, and have been well researched. As examples for this, the technical books from Springer-Verlag (publishers), xe2x80x9cPsychoacousticsxe2x80x9d (1982) and xe2x80x9cElectroacousticstxe2x80x9d(1984) by E. Zwicker are named. The cited overriding effects are also described in those books.
Consequently, the object is set of expediently letting noises created by the controlling of the aggregates, which the passengers of the vehicle cannot deliberately influence, or which have a great potential of being disturbing, occur when they are overridden by passenger compartment noises of the vehicle, so as not to disturb the passengers. The passenger compartment noises can likewise proportionally include environmental noises, travel noises and/or operating noises of individual aggregates, other noises like conversation, caused by the passengers, as well as devices installed in the passenger compartment, such as fans, audio systems or audio components, computers, etc.
The device according to the present invention, as well as the control unit and method for controlling at least one aggregate in a vehicle, in response to which passenger compartment noises appear, have the advantage that, by using them, the aggregate is controlled as a function of the occurring passenger compartment noises and/or of at least one variable representing the passenger compartment noises, that a reduction in the scope of the actually possible function can frequently be avoided without having to do without comfort with respect to noise perception.
That means that expediently in noise ranges or the appropriate operating ranges in which noise development of the individual aggregates in the vehicle can be overridden or masked by the already present, generally desirable passenger compartment noises, the aggregates can be operated in full functional and performance scope, without thereby perceptible, additional noise development being created. If the aggregate noise at full function and performance cannot be overriden, then, if possible, function and performance can be reduced optimally with respect to noise.
Thereby, advantageously, the aggregate or aggregates is/are controlled as a function of the correlation between the noise caused by the aggregate and/or at least one variable representing it and the passenger compartment noises and/or at least one variable representing this, that is, a control signal is generated as a function of it, or adapted.
Expediently, the correlation is designed as a comparison of the various noises or the variables representing them, as the case may be. For this, advantageously overriding effects of the passenger compartment noises or of the variables representing them are then used.
In this connection, in order to be able to use expediently all overriding effects, spectral and/or temporal data on the noise caused by the aggregate and on the passenger compartment noises are ascertained, and these are then advantageously correlated. One can thereby use, for example, post-overriding and/or simultaneous overriding and/or possibly also pre-overriding by the passenger compartment noises as an effect.
Advantageously, the passenger compartment noises and the noises caused by the aggregate or the aggregates, as the case may be, are represented by a sound variable such as, for instance sound pressure and/or loudness. Consideration of spectral and/or temporal data succeeds here in each case by the expedient use of a sound variable level or by using a psychoacoustic variable, such as specific loudness level plotted against time and/or frequency.
Besides that, reduction in disturbing noises or noise components contributes advantageously to riding safety, in addition to riding comfort, because distraction by disturbing noises can at least be diminished, if not totally eliminated.
It is of further advantage, also perhaps for reasons of cost pressure or rising performance requirements, that noise-wise non-optimized aggregates and their controls can be operated inconspicuously with respect to noise.
Still more advantages may be noted from the features of the claims and the specification.